2001 Future Energy Challenge

Specification Expectation

Inverter Specifications

The inverter project results will be judged against a set of objective specifications while achieving the example design targets shown below. The design concept should target a 10 kW system, while teams are asked to construct a 1.5 kW prototype to demonstrate their accomplishments. The target design requirements for the 10 kW system given below are minimums that need to be reached to win the Challenge Award of $50,000.  Scoring will be set up such that improvements beyond the minimums are beneficial to the team. More detail will be published in the official 2001 Future Energy Challenge Rules.

 
Design Concept/Function, 10 kW System Minimum Target Requirement
1. Manufacturing cost No more than $500 when scaled to a 10 kW design in high-volume production.
2. Complete package size A convenient shape with volume less than 50 L.
3. Complete package weight Mass less than 32 kg for a 10 kW unit, not including energy sources or batteries.
4. Output power capability 10 kW continuous. Single-phase split 120V/240 V, 60 Hz output suitable for domestic applications.  Each of the split outputs should provide 0 to 5 kW continuous, with the total not to exceed 10 kW.  Output current rating should support up to 10 kVA total loading continuously.  
5. Input source 48 V dc nominal source (tolerance range 42 V to 72 V) with slow transient characteristics. See the source transient behavior given in the Test Considerations section below.
6. Overall energy efficiency Higher than 90% for 10 kW resistive load.
7. Total harmonic distortion Output voltage THD: less than 5% when supplying a standard nonlinear test load.
8. Safety The system is intended for safe, routine use in a home or small business by non-technical customers.
9. Voltage regulation Output voltage tolerance no wider than ±6% over the full allowed line voltage and temperature range, from no-load to full-load. Frequency 60±0.1 Hz.
10. Acoustic noise No louder than conventional domestic refrigerator. Less than 50 dBA sound level measured 1.5 m from the unit.
11. Electrical noise Able to meet FCC Class A--industrial requirements for conducted and radiated EMI.
12. Protection Self-protection against output short circuit, over current, over temperature, over voltage, and under voltage or loss of input source with no damage caused by any of these.
13. Environment Suitable for indoor installation in domestic applications, 10°C to 40°C possible ambient range.
14. Lifetime The system should function for at least ten years with routine maintenance when subjected to normal use in a 20°C to 30°C ambient environment.
15. Technical report Design, simulation, experiment results, lifetime analysis, and cost study.


Hardware Prototype

To confirm the design concept, function, and the benefits of any new innovations, teams are expected to construct a working prototype scale system. The prototype nominal power level of 1.5 kW has been selected to facilitate both the student team design process and the final competition evaluation process. Prototypes should be fully functional, to meet the specifications given below. Late in Spring 2001, submitted reports and other materials will be evaluated by the judges. A small group of teams will be selected as Finalists, and supported to travel to a Final Competition at a national test site. At the site, prototypes will be tested against the specifications to help validate the system design and the team's concepts.

 
Prototype Specifications, 1.5 kW Scale System
1. Output power rating 1.5 kW continuous.
2. Phase(s) Split single-phase, each output rated for 0 to 750 W, not to exceed 1500 VA total.
3. Output voltage 120 V/240 V nominal. Frequency: 60 Hz ± 0.1 Hz. Standard outlets for loads:  two NEMA type 5-15R receptacles for 120 V loads and one NEMA type 6-15R receptacle for 240 V loads..
4. Battery power Team may elect to use a lead-acid battery or set, with total nominal rating below 500 W-hr, for control power or as a temporary source. If this is used, charging and charge management must be provided, such that charge is unchanged at the end of a 24-hr test sequence.  ("Nominal" refers to the product of nominal volts and amp-hours based on a 10-hour or 20-hour discharge.)
5. Safety The final rules will contain detailed safety information. No live electrical elements are to be exposed when the unit is fully configured.
6. Grid and source interaction The inverter is intended as a stand-alone unit for remote power or backup power. No power (or current) backfeed to the source is permitted.
7. Inrush and current limits Maximum current drawn from the fuel cell shall not exceed 55 A under any circumstances, except that a peak short-term current pulse drawn from the input source at start-up or connection shall not exceed 100 A.  Duration of this short-term pulse shall not exceed 5 ms.
8. Storage temperature range 0 to 60°C
9. Operating ambient temperature range 10 to 40°C
10. Other ambient Intended for indoor applications, non-condensing humidity environment, but must be spillproof.
11. Shipping environment Can be shipped by conventional air freight or truck freight.
12. Protection Over current, over voltage, short circuit, over temperature, and under voltage. No damage caused by output short circuit. The inverter must shut down if the input voltage dips below the minimum input of 42 V.  Inverter should not self-reset after a load-side fault.  IEEE Std. 929 is a useful reference.
13. Design input source type Fuel cell, photovoltaic, microturbine or other qualified renewable energy sources. Prototype tests will use a fuel cell system with a nominal rating of 48 V dc, as listed below, and a power supply configured for 48 V dc output.
14. Electromagnetic interference Per FCC 18 Class A -- industrial (not subject to test)
15. Communication interface RS232 or USB standard computer interface. Standard commercial software to be provided by the team to the test lab for acquiring any inverter internal data and recording it via a conventional spreadsheet.  (Provision for internal data is optional, but a standard interface is to be provided if internal data acquisition is present.)
Prototype Test Considerations
1. Inspections All prototypes of approved Finalist teams must pass safety inspection prior to operation. All prototypes must function correctly during a 15-minute initial operation check with a power supply input before proceeding to fuel-cell tests.
2. Test energy source: voltage Prototypes will be tested with a fuel cell source, 48 V nominal (42 V to 72 V range). Nominal power: 1.5 kW continuous measured at inverter output.
3. Test energy source: power 1.5 kW or less, continuous output referenced to inverter output (actual source power will provide up to 1.8 kW to account for inverter losses).
4. Test energy source: transients Initial Startup: 90 s to initial steady state.

Short term (unadjusted fuel cell inputs): 10 s to new steady state.

Long term (adjusted fuel cell inputs): 60 s to new steady state (from idle and above).
5.  Input current transients (ripple). (Note that these limits match those from the NETL PowerPoint presentation from the March meeting in Anaheim.) Peak-to-peak current ripple measured from the fuel cell, relative to the average current, over the inverter output load range
  • 120 Hz ripple:  < 15% from 10% to 100% load, not to exceed 0.6 A for lighter loads.
  • 60 Hz ripple: < 10% from 10% to 100% load, not to exceed 0.4 A for lighter loads.
  • 10 kHz and above: < 60% from 10% to 100% load, not to exceed 2.4 A for lighter loads
  • >120 Hz to <10 kHz, limit linearly interpolated between the 120 Hz and 10 kHz limits.
  • Teams will benefit in scoring for lower ripple levels. Maximum points will be received for ripple levels a factor of ten below the above maximum limits
  • Transients below 60 Hz represent "load following" action of the system, and should track the Maximum Available Current signal from the fuel cell to

    within 1% for purposes of both fuel cell integrity and efficiency.
6. Test energy source: control interface, signals from energy source to inverter a)  Fuel Cell Trip -- Digital TTL level, high=Fuel Cell Operable/Ready, low=Fuel Cell Trip/Not Ready.

b) Available Power Level -- Analog 0-5 V signal representing the maximum power available from the source at a given moment.  
7. Test energy source: control interface, signals from inverter to energy source a) Inverter On/Off -- Digital TTL level, high=On, low=Off. Tells fuel cell to start up or to shut down.

b) Power Level Control -- Analog 0-5 V signal to request a power level from minimum (idle) to maximum.  Tentative gain setting is 1.8 kW full scale (360 W/V).
8. Test duration Operation will be tested for up to 24 hr continuous, total.  The test sequence will include load tests with fuel cell input and performance tests with a power supply input arranged to simulate a fuel cell.  The test sequence will be specified in a separate spreadsheet.
9. Test loads Linear load: Resistive load and inductive load with 0.8 power factor. Nonlinear load: rectifier load similar to computer power supplies, specified here.

An additional test load with dynamic characteristics will be used to model a 24 hr domestic load cycle. Circuit models for test loads will be provided.
10. Typical operation tests Tests for steady-state performance (including regulation and harmonic distortion), protection, robustness to external faults, acoustic noise.  Test methods will conform to IEEE Standard 1515.
11. Source interface tests Tests for transient loads and interaction with the input fuel cell. Load ramp rates will be examined to determine suitability for the fuel cell application.

Specification Intent

The specifications are intended to provide guidance rather than an exhaustive list of requirements. All teams are encouraged to develop novel solutions and test a wide range of ideas. The long-term purpose is to develop cost-effective technologies that will bring alternative energy to homes and businesses. Judges will be encouraged to consider the spirit, innovation, and future promise of each team's work when reviewing entries.

Design Restrictions

In general, any electrical, electronic, energy, mechanical, or other component may be used in the 10 kW system design. Keep in mind the cost considerations and the intended safe use in domestic applications. Both factors will limit the feasible range of component choices.

Awards

The $50,000 Challenge Award, provided by the U.S. Department of Energy,  is given for highest score among entries meeting all minimum requirements for the 10 kW system design, as confirmed through reports and prototype tests.  Program Awards, provided by the U.S. Department of Defense, in the amount of up to $5,000 each, with a total of $25,000 to be awarded, will be given for the best results in specific topic areas (such as best thermal design, packaging, prototype quality, reports, and others).

Period of Competition and Key Dates

September 1, 2000 to August 31, 2001, with an Awards Banquet to be held in September or October 2001.

Project report due date:  June 15, 2001.  Test sequence dates:  the week of August 13, 2001.

Judging Panels and Judging

Experts from IEEE Power Electronics Society, Industry Applications Society, Industrial Electronics Society (and others to be announced), and representatives from manufacturers, national labs, independent test labs, utilities, and R&D engineers.

Student team project results will be judged based on cost effectiveness, performance, quality of the prototype and other results, engineering reports, adherence to rules and deadlines, innovation, future promise, and related criteria. Each aspect of judging will be scored according to a point list and Test Protocol published in the 2001 Future Energy Challenge Rules.

Judging involves four primary steps:

  1. Judging of the Project Reports.  The judges will be asked to score the Project Reports based on quality of the design, quality of the results, and quality of the report.  The judging results will be used to identify up to five Finalist Teams that will be invited to participate in tests at the National Energy Technology Laboratory, Morgantown, West Virginia.
  2. Quantitative Scoring.  Each Finalist team will receive a point score based on actual test results.
  3. Qualitative Scoring.  Each Finalist team will be evaluated based on a presentation at the test site, based on quality of documentation and prototype, and based on other aspects of the rules and specifications.
  4. The two or three teams with the designs judged to have the lowest cost will have their designs forwarded to one of our industrial partners for a detailed costing analysis.  The Challenge Award recipient must achieve the $500 cost target based on this analysis.

Project Report

Each team is expected to submit a formal engineering report that describes the design, simulation and test results, project activities, and prototype performance.  This Project Report should be written to address three key objectives:

  1. Present the team's 10 kW inverter design and report on the actual project activities.
  2. Demonstrate that the design will meet the specifications and requirements.
  3. Demonstrate operational success with the prototype hardware sufficient to qualify the team as a Finalist in the evaluation of the judges.  

Only those teams with functioning prototypes will qualify as Finalists, so thorough demonstration of actual test results from prototype hardware should be an important element of the Project Report.  Teams that are not able to develop fully functional hardware will still be eligible for Program Awards based on the Project Report.

    Report Format and Content Requirements

Project reports should not exceed 50 pages, double-spaced on 8 1/2" x 11" paper.  The main font size should not be smaller than 11 point.  The original copy of the report should be signed by the team's faculty advisor and the authors of the report.  A title page, signature page, table of contents, abstract, and list of references should be included but are not counted as part of the 50-page limit.

Project reports should include, at a minimum:

  • Design rationale and feature description.
  • Basic performance evaluation (through simulation and other means).
  • Cost evaluation based on the spreadsheet developed by the Organizing Committee.
  • Analysis of theoretical and experimental results.
  • A discussion of project management, the team's organization and operation, and the educational impact of the project.

In addition to the primary 50-page report, an Appendix should be provided that includes:

  • Detailed schematics and unusual material-safety data sheets.
  • Operating instructions for the prototype hardware.  (A final version of the operating instructions are to be shipped to Morgantown with the Finalist prototypes.)

Teams are encouraged to include certain additional items in the Appendix:

  • Biographical material about team members.
  • Documentation about special course offerings that were associated with the project.
  • Copies of publicity materials that the team would like to share with organizers.

Other information that the team believes will validate the design and help the judges qualify the team as a Finalist should be provided in the 50-page report based on the best judgment of team members and faculty advisors.  The report is not intended to serve as a "User Manual" for the inverter design or for the prototype, but it should include enough operating detail to permit an experienced technician to connect and test the prototype.  However, if a team wishes to prepare a user manual, this is encouraged.  It should be provided as a separate document, and will not be considered part of the report judging process.

    Due Date

The Project Report must be received at the address below by close of business on June 15, 2001 for full consideration. Project reports sent to Los Angeles will be assembled and forwarded to Vancouver for processing. Ten bound copies and one unbound copy of the report must be sent to:

Robert Myers                                             Phone: (310) 446-8280
Administrative Secretary                             Fax: (310) 446-8390
IEEE Power Electronics Society                 E-mail: bob.myers@ieee.org
799 North Beverly Glen
Los Angeles, CA 90077

Alternatively, the Project Report will still receive full consideration if the required copies are received by the close of business on June 18, 2001 at

Robert Myers, Future Energy Challenge
c/o Prof. William Dunford
Dept. of Elec. Eng.
University of British Columbia
2356 Main Mall
Vancouver V6T 1Z4
CANADA

Phone: (604) 822-6660

For teams with members who will be attending the IEEE Power Electronics Specialists Conference in Vancouver, British Columbia, it is acceptable to deliver the report copies in person to Robert Myers at the registration desk by the close of business on Monday, June 18, 2001.

 
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